Turbine airfoil components containing ceramic-based materials and processes therefor

A turbine blade of a gas turbine engine, the blade comprising:

• a first subcomponent comprising an airfoil portion and a blade tip nub that is located at a tip of the airfoil portion and is wider in cross-section than the airfoil portion, the first subcomponent being formed of a ceramic-based material;
• and
• a second subcomponent comprising a casting formed of a metallic material and attached to the first subcomponent by casting the metallic material in-situ around the blade tip nub of the first subcomponent such the blade tip nub is entirely encased within the metallic material that forms the second subcomponent and the second subcomponent is retained on the first subcomponent by the wider cross-section of the blade tip nub, the second subcomponent comprising a blade tip shroud portion having at least one off-axis geometric feature that results in the second subcomponent having a more complex geometry than the first subcomponent,
• further comprising at least one hole through the blade tip nub, wherein some of the metallic material is within the hole and interconnects regions of the second subcomponent that are separated by the blade tip nub.